Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Unit
Organic Chemistry
785 practice questions
Topics covered
Practice questions
541–550 of 785
Question 541
6 marks · Normal
Answer and see the solution →The two main industrial sources of ethanoic acid are laboratory oxidation of ethanol and microbial fermentation to produce ethanol. The steps below investigate both processes.
(a)[3 marks]A laboratory technician oxidises 4.6 g of ethanol (CH2OH, molar mass = 46 g/mol) using excess potassium dichromate(VI) in dilute sulfuric acid as the oxidising agent. Calculate the maximum mass of ethanoic acid (COOH, molar mass = 60 g/mol) that could be obtained.
(b)[1 mark]Explain the role of dilute sulfuric acid in the oxidation of ethanol with potassium dichromate(VI).
(c)[2 marks]Another technician produces ethanol by fermentation. State the conditions required for the fermentation of glucose to produce ethanol.
Question 542
6 marks · Normal
Answer and see the solution →Ethanol can be prepared by fermentation or it can be oxidised in the laboratory.
(a)Describe how ethanol can be oxidised using potassium dichromate(VI) in dilute sulfuric acid. Include what you would observe during the process.
(i)[1 mark]Describe the method used, including reagents and condition.
(ii)[1 mark]State the observable colour change that shows oxidation has occurred.
(iii)[1 mark]Name the organic product formed.
(b)Explain how ethanol can be produced by fermentation. Include two conditions that are essential for this process.
(i)[1 mark]State the process used and the starting material.
(ii)[2 marks]Give two conditions that ensure ethanol is produced, not other products.
Question 543
7 marks · Hard
Answer and see the solution →Ethanol can be produced via different industrial methods. One method involves the hydration of ethene, and another involves fermentation of sugars.
(a)[1 mark]State the word equation for the hydration of ethene to form ethanol.
(b)[1 mark]Write the balanced symbol equation for this reaction.
(c)[2 marks]Fermentation is an alternative method for producing ethanol. List two advantages of using fermentation compared to hydration of ethene.
(d)[2 marks]State one disadvantage of ethanol production by fermentation and one disadvantage of ethanol production by hydration of ethene.
(e)[1 mark]Explain why some countries prefer one method over the other for ethanol production.
Question 544
7 marks · Hard
Answer and see the solution →The table shows two industrial methods for producing ethanol: hydration of ethene and fermentation of glucose.
(a)[3 marks]State the temperature, pressure and catalyst required for the hydration of ethene to make ethanol.
(b)[2 marks]Compare the energy requirements for the hydration of ethene and fermentation methods. Give one reason for the difference.
(c)[2 marks]State one advantage and one disadvantage of the hydration method compared to fermentation.
Question 545
7 marks · Hard
Answer and see the solution →Only some of the ethene reacts in the industrial hydration process for ethanol.
(a)[2 marks]Describe how unreacted ethene is dealt with in the hydration of ethene process.
(b)[2 marks]Explain how this affects the efficiency of ethanol production.
(c)[3 marks]Compare one disadvantage and one advantage of recycling unreacted ethene in this process to fermentation methods.
Question 546
1 mark · Easy
Answer and see the solution →Name the carboxylic acid that is the main acidic component in vinegar.
Question 547
3 marks · Easy
Answer and see the solution →This question is about drawing carboxylic acids.
(a)[1 mark]State the number of carbon atoms in methanoic acid.
(b)[2 marks]Draw the displayed formula for ethanoic acid.
Question 548
2 marks · Easy
Answer and see the solution →Give the name of the unbranched carboxylic acid with the molecular formula .
Question 549
3 marks · Easy
Answer and see the solution →The table shows the molecular formulae of four carboxylic acids.
Name Molecular formula methanoic acid CH2O2 ethanoic acid C2H4O2 propanoic acid C3H6O2 butanoic acid C4H8O2 (a)[1 mark]Which acid in the table has the greatest number of hydrogen atoms?
(b)[1 mark]How many carbon atoms does ethanoic acid have?
(c)[1 mark]Give the name of the acid with formula .
Question 550
1 mark · Easy
Answer and see the solution →What is the name of the carboxylic acid with the unbranched chain and molecular formula ?